The water billing ordinance that passed easily at this week’s Finance Committee meeting could have a rougher time when it goes before the full City Council on Monday.

The reason is a letter sent to City Council members by Chief Financial Officer John Condon, telling them he will not be able to certify the proposed ordinance.

As the financial officer, Condon must look at any financial obligation the city enters into – typically a yearly budget or a bond – and certify that, in his opinion, the city will either have the money to pay the obligation without cuts to city services – or it won’t.

Or, in this case, that he can’t tell.

In his letter, Condon said he can’t certify the ordinance because it would create open-ended costs for the water and sewer enterprise fund that are impossible to estimate.

With a budget that is counting on receiving 99.5 percent of the water and sewer revenue it took in last year, he said he couldn’t guarantee those added costs wouldn’t affect services.

The ordinance approved by the Finance Committee deals with how to resolve customer accounts that have had years of estimated bills.

It says residents who received more than two years of under-estimated bills can only be billed for the last two years’ worth of that underestimated usage.

That provision, called the “two-year look-back,” is already on the books as an administrative policy for current customers with disputed bills.

The proposed ordinance would make that policy permanent, available to residents in the future who find themselves in a similar situation.

In his letter, Condon said the change could mean a “significant loss of revenue to the water utility, the impact of which cannot be reliably estimated, because it is impossible to know how many customers in the future might avail themselves of its provisions.”

The council can still approve the ordinance without Condon’s certification, but it will likely make their decision harder.

“I want to see us be able to take care of (this issue) without going into debt or laying people off because we have to pay $100,000,” Ward 2 Councilor Tom Monahan said, reacting to Condon’s decision. “We all want this to end. We want a solution. But we don’t want helter-skelter. We want to make sure it’s done right.”

Council President Paul Studenski said he’d like to see a compromise amendment added that would allow the ordinance to go through with Condon’s certification.

“I would have to be very tentative (in voting for the measure without Condon’s certification),” Studenski said. “I’d want to have a compromise occur.”